GenericLUT Struct Reference

A generic K-input LUT pattern that can implement any boolean function with up to K inputs using a lookup table. More...

Inheritance diagram for GenericLUT:

Collaboration diagram for GenericLUT:

Public Member Functions
	GenericLUT (mlir::MLIRContext *context, unsigned k)
bool	match (const Cut &cut) const override
	Check if a cut matches this pattern.
llvm::FailureOr< Operation * >	rewrite (mlir::OpBuilder &rewriter, Cut &cut) const override
	Return a new operation that replaces the matched cut.
double	getArea () const override
	Get the area cost of this pattern.
DelayType	getDelay (unsigned inputIndex, unsigned outputIndex) const override
	Get the delay between specific input and output.
unsigned	getNumOutputs () const override
	Get the number of outputs this pattern produces.
StringRef	getPatternName () const override
	Get the name of this pattern. Used for debugging.
Public Member Functions inherited from circt::synth::CutRewritePattern
	CutRewritePattern (mlir::MLIRContext *context)
virtual	~CutRewritePattern ()=default
	Virtual destructor for base class.
virtual bool	useTruthTableMatcher (SmallVectorImpl< NPNClass > &matchingNPNClasses) const
	Specify truth tables that this pattern can match.
virtual LocationAttr	getLoc () const
	Get location for this pattern(optional).
mlir::MLIRContext *	getContext () const

Public Attributes
unsigned	k

Detailed Description

A generic K-input LUT pattern that can implement any boolean function with up to K inputs using a lookup table.

Definition at line 43 of file GenericLUTMapper.cpp.

Constructor & Destructor Documentation

GenericLUT()

GenericLUT::GenericLUT ( mlir::MLIRContext *  context, unsigned  k  )

inline

Definition at line 46 of file GenericLUTMapper.cpp.

Member Function Documentation

getArea()

double GenericLUT::getArea ( ) const

inlineoverridevirtual

Get the area cost of this pattern.

Implements circt::synth::CutRewritePattern.

Definition at line 86 of file GenericLUTMapper.cpp.

getDelay()

DelayType GenericLUT::getDelay ( unsigned  inputIndex, unsigned  outputIndex  ) const

inlineoverridevirtual

Get the delay between specific input and output.

NOTE: The input index is already permuted according to the pattern's input permutation, so it's not necessary to account for it here.

Implements circt::synth::CutRewritePattern.

Definition at line 91 of file GenericLUTMapper.cpp.

getNumOutputs()

unsigned GenericLUT::getNumOutputs ( ) const

inlineoverridevirtual

Get the number of outputs this pattern produces.

Implements circt::synth::CutRewritePattern.

Definition at line 96 of file GenericLUTMapper.cpp.

getPatternName()

StringRef GenericLUT::getPatternName ( ) const

inlineoverridevirtual

Get the name of this pattern. Used for debugging.

Reimplemented from circt::synth::CutRewritePattern.

Definition at line 98 of file GenericLUTMapper.cpp.

match()

bool GenericLUT::match ( const Cut &  cut ) const

inlineoverridevirtual

Check if a cut matches this pattern.

This method is called to determine if a cut can be replaced by this pattern. If useTruthTableMatcher() returns true, this method is only called for cuts with matching truth tables.

Implements circt::synth::CutRewritePattern.

Definition at line 49 of file GenericLUTMapper.cpp.

References circt::synth::Cut::getInputSize(), circt::synth::Cut::getOutputSize(), and k.

rewrite()

llvm::FailureOr< Operation * > GenericLUT::rewrite ( mlir::OpBuilder &  builder, Cut &  cut  ) const

inlineoverridevirtual

Return a new operation that replaces the matched cut.

Unlike MLIR's RewritePattern framework which allows arbitrary in-place modifications, this method creates a new operation to replace the matched cut rather than modifying existing operations. This constraint exists because the cut enumerator maintains references to operations throughout the circuit, making it safe to only replace the root operation of each cut while preserving all other operations unchanged.

Implements circt::synth::CutRewritePattern.

Definition at line 54 of file GenericLUTMapper.cpp.

References circt::synth::Cut::dump(), circt::synth::Cut::getInputSize(), circt::synth::Cut::getRoot(), circt::synth::Cut::getTruthTable(), circt::synth::Cut::inputs, and k.

Member Data Documentation

k

unsigned GenericLUT::k

Definition at line 44 of file GenericLUTMapper.cpp.

Referenced by match(), and rewrite().

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The documentation for this struct was generated from the following file:

• /home/runner/work/circt-www/circt-www/circt_src/lib/Dialect/Synth/Transforms/GenericLUTMapper.cpp